Bug o’the Week – Forked Fungus Beetle Redux

Howdy, BugFans,

The BugLady has been out counting migrating raptors.  Here’s a rerun of an episode about an amazing beetle that the BugLady encountered in the late spring of 2014.

Every once in a while, life hands you a special treat.  Late one recent afternoon, the BugLady was walking through the beech woods, moving far too slowly, considering the size of her mosquito escort, scanning a fallen log that was adorned with a few deteriorating shelf fungi (can you spell “bug-nerd?”).  Suddenly, part of a fungus twitched.

If you’re singing along, we’re on page 192 of your Kaufman Field Guide to Insects of North America or page 583 of the Audubon Society Field Guide to North American Insects and Spiders – the forked/horned fungus beetle (Bolitotherus cornutus) (“crowned”).  The Forked fungus beetle is in the Darkling beetle family Tenebrionidae and is the only species in its genus.  It’s found east of the Mississippi, at night, in the woods, in the company of woody, polypore shelf fungi.

Males look like half-inch long “triceratops.”  Their horns can vary in size quite a bit, and most males have a small, forked, rhino-like horn at the end of their snout https://bugguide.net/node/view/788389/bgimage that the BugLady does not see in her photographs (hers is a bi-ceratops).  Females don’t have horns, but the lower edges of their heads are widened, and they wear an extra bit of armor plate on their opposite ends (more about that later).  They are drab, knobbed, pitted, exceedingly “thick-skinned,” and primordial.  Oh, but then there’s that beautiful gold fringe on the underside of the male’s horns https://bugguide.net/node/view/1864012/bgimage – The Beetle with the Fringe on Top.  It has been suggested that the hairs serve some general sensory function, but the BugLady couldn’t find any corroboration of that, and considering the Forked fungus beetle’s lifestyle, the hairs must take quite a beating.

About the natural history of the Forked fungus beetle we know plenty, thanks to research done in the 1950’s by M. Pferrer Liles and in the ‘60’s by Ann Pace (http://www.americaninsects.net/b/forked-fungus-beetles.html).  All stages of the beetle live, overwinter, reproduce and feed in/on woody shelf fungi (here in God’s Country they like the “artist’s fungus,” Ganoderma applanatumhttps://bugguide.net/node/view/422117/bgimage.  Once they find a good fungus, a small population of beetles may occupy it for as long as nine years, moving on when the fungus is no longer usable.  Larvae https://bugguide.net/node/view/1519099/bgimage turn the fungus into a honeycomb of tunnels.  Though there may be several larvae in a tunnel, they stay out of each other’s way; but if, in its travels, a larva stumbles across a Forked fungus beetle pupa, it might cannibalize the pupa.  M. Pferrer Liles noted that larval tunnels often contained masses of white mycelium (fungal strands) that had grown around and permeated the body cavity of a dead Forked fungus beetle larva.  Fungus mummifies larva – sounds like something the BugLady saw on “The X-Files.”

They have few predators.  A braconid wasp parasitizes the larvae, and a few nocturnal mammals try to eat them (more about that later, too).

So, what was the twitching all about?  The male initiates courtship by climbing onto the female, facing the opposite direction and griping her elytra (hard wing covers).  Scientists have actually measured a Forked fungus beetle’s grip strength, because having won Fair Maid, he may be dislodged by the horns of her other ardent suitors.  Males use the horns in pushing contests, and the guy with the biggest horns usually wins; likewise, bigger beetles have longer legs and a stronger grip.  Anyhow, there he sits, rubbing her head with his feet and, yes, twitching.  In this position, the underneath of his abdomen rubs against two “tubercles” on the top of her thorax.  The friction may produce a rasping sound that can be heard six or more feet away (the BugLady didn’t hear it, but the sound is typically made at night, and the movements can be made without producing the sound).  Courtship may last several hours.

When copulation is imminent, he turns around so they are facing the same direction.  According to one source, females do not pick their suitors, but they can decide which male shares his bodily fluids with them.  If she is not receptive to the male, she can block the transfer of his spermatophore by not opening the heavy plates at her rear.  After mating, the male stays in place for a long time, guarding his investment from other males.

A female lays very few eggs a year (a dozen at most), and before each egg, she must court.  Eggs are laid singly, in the early evening, in cracks on the tops and sides of the fungus.  She picks her nursery carefully – studies have shown that larvae that develop in larger fungi not only have a better survival rate, but the male larvae will have larger horns when they mature (and they’ll get all the girls).  Once laid, each egg is plastered over with what was tactfully described as “a dark, excrement-like material” that is smoothed down by hairs on the female’s abdomen.  Here are some pictures of life stages https://bugguide.net/node/view/97208/bgimage.

Forked fungus beetles lead unhurried lives.  The larvae stay in their eggs for several days after hatching, eating the capsule itself before burrowing into the spore-bearing tissues of the fungus.  New adults stay in their pupal cases for a few days after emerging, until their color darkens (here’s a newly emerged male http://bugguide.net/node/view/97192/bgimage).  An adult may live for four or five years, never venturing far from its natal fungus.  In fact, until 1999 scientists were unsure about whether Forked fungus beetles could even fly (they can), and assumed that FFBs hoofed it across the forest floor to new sites.  There are two generations per year; larvae overwinter within their fungi; adults stay in fungi, decaying stumps, and under tree bark.

It’s hard to imagine that a beetle that looks as though it heaved itself up out of the very wood itself would need a sophisticated defense system, but the Forked fungus beetle has a dandy one.  Oh, sure, a startled adult Forked fungus beetle, like many other kinds of beetles including Tenebrionids, plays dead (death feigning).  It tucks its legs into dedicated grooves on the underside of its body, and blends in with its surroundings.  But, it’s got a chemical trick up its sleeve, too.

When it feels threatened, a Forked fungus beetle releases a nasty-smelling, irritating potion that causes a potential predator to reconsider.  Rather than squirting the liquid like a squeeze bottle, Forked fungus beetles carry the chemical deterrent in two “eversible” abdominal glands that turn inside out like a pocket.  What’s unique is the timing and the trigger.

In Secret Weapons, Eisner says that “An unusual feature of B. cornutus is that it may extrude its glands preemptively, in response to the mere anticipation of an attack.  All you need do to cause the beetle to evert its glands is to breathe on it.  This readiness to deploy its chemical weapons may serve the beetle well, especially in defense against predators such as mice, which could afflict a fatal injury with their very first bite.”  Eisner goes on to say that the Forked fungus beetle defines a “breath” as a warm, moist, pulsing puff of carbon dioxide.  Producing a chemical defense is costly, energy-wise, and the Forked fungus beetle is unusual in using it before its predator actually makes contact.  The unfortunate herbivore that mouths an inhabited fungus may suffer the same fate.  Forked fungus beetles do not use a cannon to kill a gnat – when nibbled by an ant, they depend on the toughness of their exoskeleton.  For many close-up pictures, including some of a beetle spraying, see http://www.performance-vision.com/FungusBeetle/.

Last but not least – yes – phoresy!  Those legged, pink dots on the female’s head are mites!  A number of different species of mites have been documented on Forked fungus beetles.  In one study, researchers checked Forked fungus beetles in a museum collection for phoretic (hitchhiking) mites and found them on about one-third of the beetles.  The mites are species that live in fungi – some eat spores – and they take advantage of the Forked fungus beetle’s longer legs to get around.

Those horns remind the BugLady of one of her favorite cartoon characters, The Tick.  And as the Tick once said, “Mysteries abound.”

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Therion Wasp

Greetings, BugFans,

The BugLady stood on a boardwalk in a wetland for about half an hour trying to photograph this amazing wasp as it dodged through thickets of sedges, ferns, and orchids, staying below knee-level, never landing.  This is the best picture she got.  She ID’d it as an ichneumon wasp in the genus Therion.

A quick review of Ichneumon wasps, since we haven’t been there for a while.  Ichneumonidae is a very large family indeed, with 25,000 known species worldwide (5,000 of them in North America) and as many as 75,000 additional species that may be waiting to be discovered!  They live everywhere they can find prey (except Antarctica), and there are so many species spread out over so many areas that the life stories of most are not known.

They range in length from 1/8th of an inch to 3 inches, and some are very colorful.  Many have long, slim abdomens that flare at the end, some tipped with impressive ovipositors https://bugguide.net/node/view/2001653/bgimagehttps://bugguide.net/node/view/1950499/bgimagehttps://bugguide.net/node/view/1828581/bgimage.  With a few exceptions, Ichneumons don’t sting, and you have to mess pretty seriously with those that do in order to get them to do it.  Their long antennae (often at least half as long as their body) have lots more segments than do those of other wasps, and many species have a white or yellow band midway along each https://bugguide.net/node/view/1924235/bgimage.  They’re tough to identify – the Field Guide to Insects of North America says that most of the photos submitted to be used in the book could not be identified, even by experts.

“Ichneumon” comes from a Latin word that was derived from an Ancient Greek word meaning “tracker,” so-named because of the way females hunt for other invertebrates.  The larvae of Ichneumons are parasitoids – sometimes on spiders, but mostly on insects that have complete metamorphosis (egg–larva-pupa–adult).

She lays her egg, often accompanied by a shot of venom, on or in her prey, usually the larva of a beetle, butterfly/moth, or another wasp; and many species of ichneumon target particular genera or groups of prey.  When it hatches, her larva starts feeding on the non-essential parts of its host, keeping it alive by leaving the vital organs for last.  Without ichneumons, the world would be overrun by caterpillars.

Adults feed on nectar, sap, and water (some species also eat pollen), and bugguide.net tells us that many adult ichneumons overwinter as adults under loose tree bark.

There’s a genus of Ichneumon wasps that is named Ichneumon, and the resulting confusion between genus and family has caused some Ichneumonid experts to refer to the family as Darwin wasps.  Darwin, along with his Victorian contemporaries, was so horrified by the parasitoid lifestyle that he famously said: “I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars.”

Most sources list 14 species in the genus Therion in North America (20 globally), and they can be difficult to tell apart, so the BugLady assumed her well-worn seat, way out on that taxonomic limb and guessed that this is Therion circumflexum (no common name).  She felt better about her guess when she found a 1973 paper by C. N. Slobodchikoff, in which he states that “It has recently been shown that all North American Therion can be considered as members of a single species Therion circumflexum,”and he refers to the rest of the named “species” as morphological types.  Apparently, it’s been re-thought since then.  There’s not a huge amount of information available about the species, but at least the contributors to bugguide.net have gotten better pictures of it than the BugLady did: https://bugguide.net/node/view/644490/bgpagehttps://bugguide.net/node/view/752769/bgimagehttps://bugguide.net/node/view/482314/bgimage.

Therion circumflexum (“circumflexum” is Latin for “bent about”) is in the subfamily Anomaloninae, and its posture in flight, with outstretched antennae and an elevated rear, is typical of the subfamily.  Weighing in at a little more than an inch long, it’s one of the larger members of the genus.  It’s found not only in North America but also in the UK, northern Europe, Asia, and even North Africa, and its habitat is listed as “oak-chaparral and willows.”

They often perch vertically, and they spend lots of time grooming – antennae first, then mouth, then legs and wings, and finally, abdomen.

After mating, females fly away, but males lie on the ground for a minute or two, abdomens curled up, wings and legs splayed, looking like dead wasps, before they, too, leave.  Females search for caterpillars during zig-zag flights and also on foot, in vegetation, using their antennae.  They target the larvae of moths and butterflies, and their diet is more catholic than that of many other ichneumons.  Females locate a potential host by smell, and then they sweep their antennae over its exterior, making sure that the caterpillar isn’t hairy or spiny and therefore difficult to deliver an egg into.  If it passes muster, she uses her short ovipositor to insert an egg.  The host larva may undergo its full (though weakened) development before the Therion larva delivers the coup de grace, and the ichneumon matures within the pupa of its dead host.

Nature red in tooth and claw.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – And Now for Something a Little Different XI – Pitcher Plants

Greetings, BugFans,

The BugLady was on a wetland walk years ago when someone asked the leader “Why do pitcher plants grow here?”  His answer, simple and elegant, “Because they can.”

Indeed, there are lots of seeds that are falling off plants, blowing through the air, and being transported by birds and mammals; they’re looking for a home, but conditions are harsh in the wetlands where pitcher plants grow.  They’re exposed, unsheltered, to heat and cold, and many wetland soils are nutrient-poor – low in nitrogen, calcium, magnesium, and potassium.  These wetlands may be nutrient-stingy, too.  There’s organic matter in the system from fallen leaves, but it’s hard for plants to access because low oxygen levels in the soggy soil mean fewer bacteria, which means that decay/nutrient turnover takes a long time, and the lack of oxygen also makes water uptake more difficult.  Plants that will thrive in these places must come pre-set with adaptations that allow them to do so.

Part One – The Introductions.

Purple/Northern pitcher plant (Sarracenia purpurea) is a plant of acid bogs and neutral-to-acid fens.  It occurs throughout the East, across Canada, and along parts of the Pacific Coast as a native and as an introduced plant (the BugLady, who does not grow things, was amazed to discover that people also keep it as a house plant).  It was named after a French physician named Michael Sarrazin who lived in Canada in the closing days of the 17th century and who turned his interests to botany.  He was the first to describe the plant’s lifestyle (more about that in a sec), and he documented the Native use of pitcher plants to treat smallpox.  It was also used for fever, kidney and lung ailments, back pain, chills, and whooping cough, and it was an aid in childbirth.  The pitchers were used as drinking cups, berry containers, and in ceremonies, and the outside was sometimes carved like scrimshaw.

The hollow, trumpet/pitcher-shaped leaves – green, maroon, or green with maroon veins – fill with rainwater in spring.  One theory for the different leaf colors is age (older = redder), and another is sunlight – plants in full sun protect themselves from UV radiation by deploying red pigments called anthocyanins, but leaves in the shade don’t need them.  A healthy plant may grow five to ten new pitchers a year, and as the plant ages, multiple leaves sprouting from the same rhizome radiate around it like a rosette.  Purple pitcher plants can live for decades; the evergreen leaves persist into their second season and give energy to the plant as their replacements are growing.

The flower stalk produces a single flower that looks like a wine-red, upside-down tulip and that is pollinated by bumble bees, honey bees, and Pitcher plant flies (Fletcherimyia fletcheri).  After it’s fertilized, the flower straightens up and the petals drop off, and old seed capsules persist through the winter.

Its list of common names tells of people’s fascination with it and of some of its historical uses – Turtle socks, Side-saddle flower, Fever-cup, Smallpox plant, Indian Dipper, Huntsman’s Cup, Adam’s-Pitcher, Frog’s Britches, and Whippoorwill-boots.

Part Two – It Eats Meat.

The pitchers are a trap.  Insects are attracted to sweet nectar that’s produced by glands located in the red veins on the inside surface of the lip (they’re called extra-floral nectaries (EFNs) https://uwm.edu/field-station/ants-in-my-plants/).  Immediately below the lip, there’s a band of small, downward-facing needles that discourage insects from turning around.  Below that, the leaf is lined with slick, waxy cells that send the hapless insect sliding into the water.  An old theory says that insects come to the plant because of the “red meat” color of the veins, and that may be true of some flies, but many insects don’t see in color, so it’s more likely that nectar is the draw.

It’s a great design, but one study estimated that even a well-fed pitcher manages to collect less than 1% of its visitors!

Ants make up about 70% of its prey – their short legs make those downward-pointing needles especially daunting.  Mites, spiders, beetles, snails, millipedes, flies, springtails, wasps, and moths are among a pitcher plant’s other prey, and researchers have even found small spotted salamanders and red-spotted newts in pitchers (one small salamander would satisfy a pitcher’s nutritional needs for a long time).

The plant gets energy through photosynthesis, but the insect prey provide minerals that are missing from the soils (ant bodies, it turns out, are very high in nitrogen).  The water in the pitcher contains some digestive enzymes, though young leaves are better at producing them than older leaves are.  The enzymes do part of the digesting, and now we come to the last piece of the puzzle.

Part Three – A Cast of Thousands.

Seasoned BugFans know that the BugLady is fascinated by inquilines (Latin for “lodger” or “tenant”), those (in this case) invertebrates that shelter in structures built by others, like galls, nests, hives, etc.  Some simply co-exist with their host without interacting, and some perform light housekeeping chores by feeding on debris in a nest.

Larvae of the Purple pitcher plant mosquito (Wyeomyia smithiihttps://bugguide.net/node/view/1241580/bgpage live in the pitcher year round, overwintering in the frozen water and coexisting with the very carnivorous larvae of the Pitcher plant midge https://www.inaturalist.org/taxa/225007-Metriocnemus-knabi.  As spring advances, algae arrive in the pitcher, followed by an array of invertebrates that form a food web.

Overall, researchers have logged more than 165 species of inquilines in the water of purple pitcher plants – bacteria, mites, protozoans, copepods, nematode worms, rotifers https://en.wikipedia.org/wiki/Habrotrocha_rosa, the larvae of Pitcher plant flies https://bugguide.net/node/view/1978019 and other fly species, and more – almost three times more than in any other species of pitcher plant.  Some of the inquilines live only in pitcher plants; all must be tolerant of poor water quality.

It’s all about recycling.  These invertebrates not only live in the pitcher plant’s water without getting digested (through the magic of “anti-enzymes”), they help to “feed” the pitcher by breaking captured animals into smaller pieces so that they’re easier for the enzymes to digest, and/or by eating the prey (and each other) and then adding nutrients to the water via their excretions.  The midge larva https://www.inaturalist.org/taxa/225007-Metriocnemus-knabi feeds on drowned prey at the bottom of the pitcher, and the tiny particles it creates are food for the filter-feeding mosquito larva.

The midge larva is selective.  In one experiment, researchers introduced into the pitchers the larvae of mosquitoes that are not normally found there, and they reported that the midge larvae ate the aliens in short order but left the larvae of the Pitcher plant mosquito alone.  They speculated that if drought conditions were to wipe out the natural inquilines, the stage could be set for the use of the pitcher by exotic species.

Nutrients and CO2 provided by its inquilines are used by the plant, and the oxygen that is released into the water through photosynthesis benefits the critters that live there.  Because the “hood” of the Purple pitcher plant is open (the hoods of some species form an umbrella over the top), nutrients can also enter the system in rainwater.

Spiders oviposit within the pitcher (some spin webs across the pitcher’s opening), and several moth caterpillars feed on the leaves, both from the inside and the outside.  A thread-waisted wasp creates a nest for her egg by chewing a hole at the base of a leaf, draining the pitcher, stuffing it with grass, and provisioning it with caterpillars.

Fun Fact about pitcher plants:

  • A Michigan man who claimed to be 125 years old attributed his longevity to drinking pitcher plant water daily (do not try this at home).

  • A pitcher plant is considered a phytotelmata, “water-filled structure produced by plants” – a mini-aquarium.  Tree holes and the water reservoirs in bromeliads are also phytotelmata.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Late Summer Reflections

Howdy, BugFans,

The BugLady has been out looking for bugs as the summer winds down; her dragonfly and butterfly surveys have been yielding fewer and fewer species these days.  It has been an odd year, phenology-wise, with many species seeming to start late and wrap up early.  Seasoned BugFans will not be surprised to hear that her camera has been drawn disproportionately to dragonflies and damselflies.

AMBUSH BUG AND PREY – A dynamite little predator and a BugLady favorite.

EASTERN TAILED-BLUE BUTTERFLIES have several generations per year, flying from May through September.  The BugLady sees them along mowed trails until the first frosts, skittering just above the grass, looking for white clover to lay their eggs on (so set your mowers above the height of those clover flowers).  The eggs soon hatch, and the larvae overwinter in the clover’s seed pods.

AZURE BLUET DAMSELFLY – Spilling over into late September, Familiar Bluets are the final bluets of the season, but the lushly-blue Azure Bluets are second-last.  What a treat!

BALD-FACED AERIAL YELLOWJACKETS aka BALD-FACED HORNETS – It’s always exciting, as the leaves start to fall, to see how close we’ve been walking to the hidden nests of Bald-faced hornets https://bugguide.net/node/view/1632691/bgimage.  Apparently, when the BugLady wasn’t paying attention, Bald-faced hornets were renamed to more accurately reflect their taxonomy, and now they’re called Bald-faced Aerial Yellowjackets (as opposed to the regular yellowjackets in the genus Vespula).  People ask the BugLady if there are any insects that she’s afraid of.  She’s not thrilled by ants (due to a misspent youth, during which she discovered that lederhosen offer no protection from an anthill), but these hornets/aerial yellowjackets do give her pause, because if you stumble into a nest, they can advance faster than you can retreat https://bugguide.net/node/view/1577524.

Why did the SWORD-BEARING CONE-HEADED KATYDID cross the road?

The egg that this SLENDER SPREADWING DAMSELFLY is inserting into the bulrush will spend the winter there in diapause (suspended animation).  In spring, it will hatch, and in the form of a “pronymph,” exit the stem and drop into the water to complete its development as a nymph/naiad over the next few months.

AMERICAN PELECINID WASPS are about 2 ½” long, and it’s mostly abdomen.  She’s harmless unless you’re a June beetle grub, living happily out of sight underground looking for potatoes, in which case she will thread that long abdomen into the soil and deposit an egg on your exterior.  She produces that egg via parthenogenesis.  What a fascinating insect!  https://uwm.edu/field-station/american-pelecinid-wasp/

WHITE-FACED MEADOWHAWK DRAGONFLY – There are about a half-dozen species of meadowhawks in the BugLady’s neck of the woods – males are red; females and young males are generally amber; and they can be tricky to tell apart.  One of the things that distinguishes meadowhawks is their sheer abundance – by mid-July, they start to outnumber the rest of the dragonflies.  The BugLady did a dragonfly survey a few years ago in which she stopped counting meadowhawks at 150 and just checked “abundant.”  Not this year.  Not on the trails she walks.

Meadowhawks have a risky reproductive strategy.  Rather than deposit eggs in water or aquatic vegetation, meadowhawks, especially White-faced Meadowhawks, gamble.  Flying in tandem near, but not over, the edge of the pond, the female lobs eggs down onto ground that she hopes will be inundated by fall rains or spring floods.  But parts of Southeastern Wisconsin had a dry fall followed by a dry spring, and the water levels never rose, and the BugLady thinks that lots of eggs got stranded.  She doesn’t think she’s seen even 30 meadowhawks since the beginning of July.

What will happen?  Maybe a wet fall will encourage the eggs of this year’s meadowhawks, but it might take a few years for the population to build back in from the edges.

A small herd of BARK LICE appeared on the BugLady’s porch rail in mid-August.  Bark lice, aka tree cattle, graze harmlessly on fungus, algae, and other little stuff on tree trunks (and porch rails).  Better than bleach.

RED ADMIRAL BUTTERFLIES (historically called Red Admirables) are everywhere – in temperate parts of North Africa, Europe, Asia, New Zealand, North and Central America, and the Caribbean.  They can get away with it because the caterpillar food plants are nettles, which are also everywhere.  Like Monarchs, they’re migratory.  They arrive from the South in May and produce a summer brood here.  The new crop of Red Admirals heads south when the flowers fade, to overwinter there, and their offspring repopulate God’s Country again in the spring.  Their populations are (inexplicably) cyclical; a few years ago we had a monster year for Red Admirals, but the BugLady saw very few this summer.

COMMON GREEN DARNERS also migrate (but it’s a little more complicated than that – Wisconsin has both a migratory and a non-migratory population of Common Green Darners).  At 3” long, these are big dragonflies.  BugLady was surrounded by them as she stood on the hawk tower near the shore of Lake Michigan in early September – she was looking for raptors, but it was all darners and BLACK SADDLEBAGS, as far out as she could scan with her binoculars.

The SPINED SOLDIER BUG is a stink bug in the genus Podisus.  Though many stink bugs are plant feeders and some are crop pests, this soldier bug is cruising the flower tops looking for caterpillars and other juicy items.

Autumnal equinox!

Kate Redmond, The BugLady 

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Two-spotted Tree Cricket

Greetings BugFans,

The BugLady had a visitor at her front door the other day – a Two-spotted tree cricket.  When they think of tree crickets, most people picture a delicate, flat, green member of the genus Oecanthus (https://bugguide.net/node/view/883267/bgpage).  Oecanthus tree crickets, with a brief nod to the Two-spotted tree cricket, were celebrated in a previous BOTW https://uwm.edu/field-station/tree-crickets/.  Today’s story is about that other tree cricket.

The Two-spotted tree cricket (Neoxabea bipunctata) (family Gryllidae) used to be grouped with the Oecanthus but was reclassified into the Neoxabea.  According to bugguide.netNeoxabea means “new tree cricket” – Xabea being yet another tree cricket genus and the one that the TSTC was assigned to before it was an Oecanthus.  Neoxabea are called the “smooth-legged tree crickets” because the Oecanthus have spines on their hind legs and Neoxabea don’t.  There are about a dozen species in the genus Neoxabea worldwide, but the TSTC is the only species north of the Rio Grande unless you count the Brownsville tree cricket (N. formosa), which barely makes it over the border and whose classification is a bit problematic.  Here’s a glamour shot – https://bugguide.net/node/view/1475840/bgimage.

There was a reference to a common name for the TSTC in Ohio – “itch bug” – that the BugLady couldn’t find anything more about.  Tree crickets, though they are (barely) capable of biting human skin, rarely do (in the BugLady’s experience, they’re too busy exiting the scene).

TSTCs, as one reference pointed out, are found over the eastern half of the country in approximately the same footprint as the original, eastern deciduous forests.  They are associated with oak, apple, maple, white pine, and a variety of other trees, and also with wild grape and sunflower.  They aren’t seen as often as their Oecanthus cousins because they tend to live higher off the ground in dense vegetation, and males sing from the undersides of leaves.

The cut of their jib is distinctly different from the other tree crickets.  Unlike the Oecanthus https://bugguide.net/node/view/37247/bgimage, they tend to be pinkish, and the male’s wings are less flared https://bugguide.net/node/view/1611999/bgimage.  Females have two dorsal spots; males don’t.

TSTCs have gradual metamorphosis – nymphs resemble the adults and there’s no resting/changing/pupal stage.  Both adults and nymphs feed at dusk and by night on the same diet of tiny insects, bits of leaves, pollen, and fungi (and the BugLady wonders if maybe the one on the screen was grazing on the algae that grows there).  They are preyed upon by wasps, including grass-carrying wasps, of previous BOTW fame, which collect them to cache for their young.

The male’s song is described as a broken trill (one source described it more authoritatively as “A plaintive, dissonant, buzzy trill at about 3.5 kHz, with a distinctive “screaming” quality.”).  He produces sound by rubbing together the ridges on each wing (a “scraper” and “file”).  In the spirit of cold-bloodedness, the warmer the air is, the more trills he generates, and he hedges his bets by chewing a hole in a leaf and positioning his wings and body over it so that the leaf acts like a megaphone.  The tympanum (hearing organs) on her front legs must be tuned to distinguish his species from others at whatever rate he’s singing.  She prefers males that sing “bass,” because they’re probably bigger and therefore have more sperm.

In a paper called “The Mating of Tree Crickets,” David Funk explains that because the sound is amplified backwards from the male, females tend to approach from the rear. He says that “When a male senses the presence of an approaching female, he stops singing and turns around to touch her with his antennae. It is thought that by “tasting” her in this way, he is able to assure that she is a member of the same species and therefore an appropriate mate.”

Their reproductive strategy includes a practice called courtship feeding. There’s a groove on the top of his thorax, between his wings, and into it oozes a substance produced by the metanotal gland, a substance that is irresistible to the female (sometimes unpaired females approach and try to feed, too).  When the female climbs on his back to reach it, she is positioned so that the male is able to insert a spermatophore into the appropriate opening.  She clings to his back, feeding, as he hangs from the vegetation https://bugguide.net/node/view/1778045/bgimage.

As she feeds, the spermatophore empties into her oviduct, and when she’s finished with the metanotal fluid, she eats the also-nutritional, empty spermatophore, too.  Says Eric Eaton in his bugeric blog, the female would undoubtedly eat it [sooner] if she did not have the more attractive metanotal secretion to lick instead.”

She punches her ovipositor deep into a small branch https://bugguide.net/node/view/238538, inserts an egg and, says Bentley B. Fulton in a 1915 Technical Bulletin for the New York Agricultural Experiment Station, “Just before depositing the egg, and while the ovipositor is embedded for its full length in the bark, the female forces out a drop of excrement, which by stretching out the tip of the abdomen, she fastens to the bark just below the hole.  After withdrawing the ovipositor she moves back, picks up the drop with her mouth and places it over the opening.  Several minutes are then spent packing it in and smoothing it out. https://bugguide.net/node/view/259844.  Fulton’s article includes some lovely, pre-digital illustrations https://orthsoc.org/sina/s576lf15.pdf.

The eggs hatch in spring and the nymphs are pretty cute – the butts-up position is a common pose https://bugguide.net/node/view/1834770/bgimage.  Here’s an excellent set of pictures of ages and stages https://orthsoc.org/sina/601a.htm, plus sounds.

Sometimes the punctures she makes as she’s ovipositing damage woody plants by weakening the twigs, but it’s seldom a problem, and one Exterminator’s website included a link to “detailed information about this fascinating insect.

Go outside.  Listen!

Kate Redmond, The BugLady

Bug o’the Week – Have You Seen This Fly???

Howdy, BugFans,

The BugLady was poking around in a wetland toward the end of May when the Black Chokeberry (Aronia melanocarpa) was in bloom.  As she photographed its flower, a syrphid fly or two buzzed in.  Any flower shot is enhanced by having an insect in it, right?

Syrphid/Flower/Hover flies (family Syrphidae) are the often-tiny, usually-black-and-yellow bee mimics that perch lightly on or hover above flowers.  Some wear patterns that are amazingly etched (an “up-side” of photography is that instead of a fleeting glance, the BugLady gets to put their pictures on the screen and enjoy the intricate tracery https://bugguide.net/node/view/2023052/bgimagehttps://bugguide.net/node/view/1611313/bgpagehttps://bugguide.net/node/view/1960381/bgimage).  Although they are designed to look like bees, they are harmless, and they’re important pollinators.

The BugLady got pretty excited when she put the picture up on the monitor – she had never seen a black syrphid fly with white spots before.  When she revisited the wetland a week later as the chokeberry faded, she couldn’t find the fly again.

Turns out that it was a Black bog fly (Parhelophilus porcus).  Parhelophilus is a small (20 species) Holarctic genus (meaning that they’re found around the northern half of the globe) with 10 species in North America.  There’s another, fairly similar, black and white Parhelophilus that also occurs in Wisconsin, but the rest of them are yellow and black.  Adult Parhelophilus flies are mostly recorded eating the nectar and pollen of asters and other composites, but in most of the few pictures that the BugLady could find of this fly, it was on white flowers in the viburnum and rose families.

Parhelophilus larvae are numbered among the rat-tailed maggots; they live in shallow waters of ponds and slow streams and, typical of the tribe Eristalini, breathe through an extended siphon at the rear of their abdomen as they recycle decaying vegetation with the other end https://bugguide.net/node/view/815670.

Here’s what the BugLady found out about the Black bog fly:

  • It is found way north, well into the Arctic.  Most of the pictures on bugguide.net were taken in New Brunswick.  It’s on the Finnish iNaturalist site, and there were some Russian hits.

  • It is a pollinator and recycling agent whose presence indicates a healthy bog.

  • The Aquatic Insects of Michigan lists it as being “widespread” in Wisconsin, and while it may be widespread, it is in fact a rare, habitat specialist here.

  • The same source says that “the systematics of the family are in flux.”

  • The larva of the Black bog fly has not been identified or described, nor have its habits been studied.

  • It looks a whole lot like Parhelophilus sibiricus, a syrphid fly that’s restricted to bogs in Siberia, and it could be the same species.

  • Writing about it in 1997, researcher F. Christian Thompson tells us that “Most of the known sites for porcus are the typical kettlehole bogs (Bingham Pond, Wilson Mills), but some (Laurel Lake site) are better described as fens bordered by spruce, fir and hemlock ……… Unfortunately, for most collected specimens, no site information is available.

  • The Wisconsin Insect Research Collection contains nine specimens of the Black bog fly, all of which were collected in Door County in 1951 (thanks, BugFan PJ).

That’s it.

Go outside – find cool stuff!

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/

Bug o’the Week – Northern Amber Bumble Bee

Howdy, BugFans,

This one’s dedicated to BugFan John – it was an honor.

The BugLady has been enjoying an abundance of bumble bees on the prairie recently, despite the fact that, along with the start of the tree cricket chorus, it is a sure sign of the impending autumn.

Quick and dirty bumble bee review:

They’re important pollinators.  They are not aerodynamically designed.  Most native bees are solitary, but bumble bees live in colonies headed by a queen, and unlike their solitary cousins, will sting to defend the nest.  Because of their ability to raise the temperature inside their thorax by shivering their wing muscles, they can fly in pretty chilly weather (other insects can do this, too, but bumble bees are the champs, warming from 55 to 98 degrees Fahrenheit in just six minutes).  They deliver ecosystem services and are considered “keystone species” – species whose absence would affect their communities (no bees = no fruits and seeds = no wildlife).  Many bumble bee species are in trouble.  For more details about all that and more, see these previous BOTWs https://uwm.edu/field-station/bumble-bee-redux/https://uwm.edu/field-station/celebrating-bumblebees/, and https://uwm.edu/field-station/rusty-patched-bumble-bee/.

“Bumblebee” or “bumble bee?”  It’s the same rule that governs the names of flies.  The folks at Minnesota Seasons explain: “The Entomological Society of America follows the convention suggested by R. E. Snodgrass, author of Anatomy of the Honey Bee (1910), when assigning common names to insects. Snodgrass states, ‘If the insect is what the name implies, write the two words separately; otherwise run them together. Thus we have such names as house fly, blow fly and robber fly contrasted with dragonfly, caddisfly and butterfly, because the latter are not flies, just as a dandelion is not a lion and a silverfish is not a fish. The honey bee is an insect and is preeminently a bee; ‘honeybee’ is equivalent to ‘Johnsmith.’”

So – the Northern amber bumble bee (Bombus borealis) aka the Boreal bumble bee is a medium-large bee in the bumble-honey-carpenter-cuckoo-digger bee family Apidae.  Called “amber” because it is, and “northern” because its range extends east from the Rockies across Canada and the northern US.  Its former range dipped farther south, even into Georgia at the higher elevations of the Appalachians.

Bumble bees need three habitats that are not too far apart – one for foraging, one for nesting, and one where the queen overwinters.  Northern Amber bumble bees are found in grasslands and agricultural fields near woods.

Their biographies are similar to those of other bumble bees.  Newly-minted queens mate in fall and overwinter on the ground, under cover.  They emerge in late May/early June in Wisconsin (not one of the super-early species) and make a nest that’s usually underground but could be in a rock pile, tree hole, or clump of grass.  South-facing, abandoned rodent burrows are favorite spots, and she often must fend off other queens who have their eyes on the same real estate.

She cares for the first brood herself, feeding nectar (carbs) and pollen (protein) to the larvae, and if it’s chilly, sitting on the eggs and using her thermoregulatory abilities to warm the brood patch on the underside of her thorax (her daughters will later regulate the temperature of the nest).  She hands off the child care, foraging, and nest maintenance duties to them when they become adults (the BugLady read somewhere that individuals in this initial brood may be smaller, because they had only one caregiver).  Populations peak in late summer as a crop of males is produced, but only the new queens will make it through the winter.

Bumble bee species have different tongue lengths, designated as “short,” “medium,” and “long,” and the length of their tongues determines what flowers they feed on.  Of course, some short-tongued bees have devised a “work-around” – making a hole at the base of a tubular flower and lapping nectar from the outside.  Northern amber bumble bees are long-tongued bees, and although you find them on composites and roses, they are able to extract nectar from the tubular flowers of clovers and vetches.

According to the Xerces Society, “more than a quarter of North American Bumble Bees are facing some degree of extinction risk.”  Northern amber populations are vulnerable along the southern edge of its range, especially in the East, but they seem to be stable in Wisconsin.  Minnesota has seen a large shrinkage of territory occupied, with the range shifting northward.

One problem in censusing bees is a phenomenon called “Shifting Baseline Syndrome.”  There are few long-term studies of bumble bees, so today’s scientists are starting in a hole – they’ve never seen the bees at their earlier population levels, and the present, diminished populations are their “baselines.”  There have been some studies of historical bumble bee numbers using museum collections; these searches show a loss both of diversity and of range starting as agriculture intensified in the middle of the last century, and some species are now “locally extirpated” (locally extinct).

Some studies suggest that the bumble bee species that are declining tend to have shorter lists of plants that they forage on, but other factors, like climate, could be contributing.  Like honeybees, bumble bees are an industry, with captive bees carted around the country.  Some of the bumble bees that are contracted out to pollinate greenhouse crops are not native, some carry diseases, and some escape to infect native bees.

How can we help?  Bee-friendly plantings (bee-friendly plantings, bee-friendly plantings), bee-friendly buffers, including hedgerows around agricultural fields and along roads, bee surveys (https://wiatri.net/inventory/BBB/getInvolved/), and fewer herbicides and pesticides.  Since rodent burrows are at a premium, some researchers are experimenting with manmade nest boxes.

Here is more information about bumble bee ID:

https://www.fs.fed.us/wildflowers/features/posters/EasternBumblebeesPoster_reduced.pdf

https://apps.extension.umn.edu/environment/citizen-science/bee-atlas/bumble-bees/docs/bumblebee_species_slides.pdf

https://www.fs.fed.us/wildflowers/pollinators/documents/BumbleBeeGuideEast2011.pdf

Go outside – watch bumble bees!

Kate Redmond, The BugLady

Seeking Homeschool Education Volunteers at Riveredge for 2021-22 School Year

At Riveredge, we always like to consider ourselves a volunteer-driven, staff supported organization. We’re seeking a few volunteers to help out with our homeschool program in this coming school year.

Specifically, we’re seeking help with the younger ages especially (4/5-year-old Dragonflies and 6/7-year-old Monarchs) but also have a need for some middle school (Sturgeon) assistance. These programs are bi-weekly on Mondays, Wednesdays, or Fridays starting on September 10th.

We’re seeking need 4 people on Mondays, 3 on Wednesdays, and 4 on Fridays. They do not need to commit to the entire year-long program though that is of course preferred. See description below.

Main Homeschool Volunteer Responsibilities

  • Helping to prepare and set up the day’s equipment
  • Helping to check the students in and helping with “ice-breakers” or crafts
  • Watching the students before, after, and during the Homeschool Ed-Ventures program to foster safety, kindness, and respect.
  • Working with small groups of students during activities
  • Have fun!

For this 9-12 am program, volunteers are asked to arrive 15 min early and stay 15 min after but this is flexible if you need to hurry elsewhere.

The only requirement is a completed background form, submitted prior to your first volunteer date. As long as everything is clear, you will be able to help in the classes.

For the day, all you would need to bring is a water bottle, snack (optional), a mask for any time spent indoors, and forecast-appropriate clothing. Volunteers will need to be ready to be outside for the majority of the program unless there is exceptionally inclement weather.

We hope you will find as much enjoyment out of the program as the kids by helping to support Riveredge and our wonderful homeschooling community!

Contact ktait@riveredge.us with questions or to forward your completed background form.

Conservation Announcement: Sandhill Lake Wildlife Sanctuary joins Riveredge!

Riveredge Nature Center is elated to announce the gift of a nearby 40-acre parcel of land entrusted to us to conserve and restore. Sandhill Lake Wildlife Sanctuary is near the main Riveredge property, though not connected, and has been donated by the Hepburn family of Cedarburg, longtime friends and supporters of Riveredge.

This property already holds a conservation easement and the location offers exciting opportunities to both conserve and improve habitat. The parcel boasts various habitats, including marshland, forest, riparian stream, agricultural land in production, post-agricultural prairie, and access to Sandhill Lake. In the upcoming years, it will be used as another education outpost for a variety of programs.

Riveredge conservation staff will conduct a thorough survey  of the property to develop a conservation restoration and management plan. Initial inspections have revealed badger dens, more than 50 species of birds, and excellent turtle breeding habitat.

From a programmatic use standpoint, we envision this location for various potential educational opportunities, including: summer camps, homeschool programs, field trips, academic partner research endeavors, and scout group outings.

When we think of real estate in the context of conservation, the funny thing about ownership titles, real estate deeds, shoreline easements is that Rusty-patched Bumble Bees, Pileated Woodpeckers, and Rainbow Trout all have no regard for such human declarations. This is why Riveredge’s conservation philosophy is to work alongside neighbors, farmers, land owners, and future environmentalists to expand how properties can become a both more beautiful and resplendent beacon for wildlife. We look forward to cultivating goodwill with our new neighbors at Sandhill Lake.

We look forward to conserving this robust habitat with efforts that will increase the native and migratory species seen on Sandhill Lake Wildlife Sanctuary, and will in turn have a positive ripple effect on the neighboring properties. With gratitude and purpose, we thank the Hepburn family for their longtime friendship and support, and for entrusting Riveredge with the earnest duty of caring for Sandhill Lake Wildlife Sanctuary.

 

Bug o’the Week – Silver-bordered Fritillary Butterfly

Howdy, BugFans,

The BugLady’s excursions onto the prairie are always enhanced by the sight of the almost-monarch-sized (2 ½”-3 ½” wingspan) Great Spangled Fritillaries sailing along among the flowers https://bugguide.net/node/view/1995412/bgimage.  They come by their names honestly – great and spangled indeed https://bugguide.net/node/view/61315/bgimage!  For more information about them, see https://uwm.edu/field-station/great-spangled-fritillary/.

This summer, she’s been lucky enough to find these beautiful, also-spangled, Silver-bordered Fritillaries (Boloria selene) alternately bustling and gliding along at the margins of wetlands.  They are in a different genus than the Great Spangled – Boloria are called the lesser fritillaries – and with 1 ½” to 2” wingspans, they are noticeably smaller.  Selene was goddess of the moon in ancient Greek mythology; a previous scientific name is Brenthis myrina, and an old common name for this species is “little myrina,” which the BugLady doesn’t understand, because myrina refers to the Amazon mythology.

Fritillaries are in the brush-footed butterfly family Nymphalidae – butterflies whose first pair of legs is reduced and “brushy” and who walk around on their second and third pairs of legs.

Silver-bordered Fritillaries are found around marshes, sedge meadows, and bogs across the northern half of the US and into Canada (in the southern part of their range they may live at higher elevations), and at another location – more about that in a sec.  They are homebodies that do not disperse enthusiastically from the enclaves where they are found.

Males patrol for females.  Females lay eggs on violets, their caterpillars’ sole food plants, though sometimes she puts her eggs on the ground or on grasses near violet plants, and then her offspring must find their first meal for themselves.  They don’t have a favorite violet – whatever’s growing nearby works for them – and they don’t appear to use non-native violet species.  Adults nectar on members of the composite, pea, and milkweed families.

They produce at least two broods each year, and the final brood overwinters as caterpillars, sheltered on the ground, in a stage of dormancy.  Some of these overwintering larvae are half-grown when they tuck in for the winter, and some are fairly recently hatched, so the appearance of adult butterflies is somewhat staggered after they awake, resume feeding, and complete their metamorphosis in spring, a phenomenon that Scudder investigated in 1889.

Silver-bordered Fritillary don’t adapt rapidly to change, and their populations are decreasing across their range.  Their numbers probably rose as European settlers whacked back the endless forests of the eastern US, creating favorable habitat.  But the resulting agricultural landscape was not friendly to them either, because wetlands were drained (so the land could be “more productive”), and because their violets were plowed up or were pushed out by the European crops.  According to Massachusetts Butterflies, roadside ditches are emerging as important habitat for Silver-bordered Fritillaries in that state.  Food specialists are, by nature, closer to the abyss than are generalists.

Spraying for gypsy moths threatens them, climate change is thinning populations of this northern-oriented species across the southern edge of its range, and they continue to be bothered by habitat loss and habitat fragmentation.

If you google Boloria selene, you’ll also get hits from across The Pond, where the Silver-bordered Fritillary is known as the Small Pearl-bordered Fritillary (as one source said, “from the series of ‘pearls’ that run along the outside edge of the underside of the hindwing”).  It’s found from Great Britain through Europe and into Asia, and, alas, its populations are declining abroad, too, due to habitat change brought by agriculture.

Like the American members of the species, the Small Pearl-bordered Fritillary is a fairly sedentary butterfly that doesn’t travel far from its natal wetland.  When habitat gets fragmented, populations get isolated, and genetic diversity diminishes.  Research indicates that when siblings of this species mate – a possibility that becomes more likely with isolation – their offspring aren’t viable.

Apropos of nothing, as the BugLady’s Dad used to say, the BugLady found this cute little bug while doing an unrelated search https://bugguide.net/node/view/22991/bgimage (she has photographed the adult, which is also awesome!), and this blog.whose first article is about insect use of swamp milkweed http://www.hiltonpond.org/ThisWeek210811.html.

Kate Redmond, The BugLady

Bug of the Week archives:
http://uwm.edu/field-station/category/bug-of-the-week/